Gall. Dark purplish, fusiform, frequently clustered bud galls with a length about I cm. and a diameter of .5 cm. Clusters of six or seven are not unusual though occasionally only three or four, or one or two may develop upon a shoot. One small shoot bore eleven galls ... The galls occur on the subterranean stems or root stalks of Aster macrophyllus [Eurybia macrophylla], pushing up through the dead leaves in the spring and when numerous preventing the development of the foliage.

Gall ovoid-tapered...at base of stem...Rhopalomyia weldi Felt

Galls were found in early spring and were described as soft, about 10 mm long and 5 mm wide, single or clustered, and purplish... Host: A. macrophyllus. Distr. Illinois